Surface material, shaft member unit, and method for wrapping the surface material.

Abstract

To provide a skin material with an improved appearance, a shaft member unit with the skin material, and a method of winding the skin material.SOLUTION: A skin material 30 of the present invention is wound around at least a portion of a ring portion 12 along the circumferential direction of the ring portion 12, and the skin material 30 is a foam resin or elastomer mold-formed to form a C-shaped or U-shaped cross-sectional shape in a plane perpendicular to the axial direction of the ring portion 12 and a parting line 36 is formed on the outer surface. The parting line 36 is arranged on a surface opposite to the ring portion 12 in the state of being wound around the ring portion 12.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a skin material, a shaft member unit, and a method for winding the skin material.

Background Art

[0002] Patent Document 1 describes a technique for forming the skin portion of a steering wheel from a resin that foams in a mold. A technique is disclosed in which a core metal is disposed in a mold, and a raw material is injected into the mold and foamed to form a skin portion in which the core metal is embedded.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to the above technique, a parting line is formed on the outer surface of the skin portion at a portion facing the inside of the mating surface of the mold. For this reason, there is a problem that the appearance of the skin portion deteriorates.

[0005] The present invention has been made in view of such a background, and an object thereof is to provide a skin material with improved appearance, a shaft member unit including the skin material, and a method for winding the skin material.

Means for Solving the Problems

[0006] An aspect of the present invention is First a skin material wound along the circumferential direction of the shaft member in at least a partial region of the shaft member, wherein in a state where a foamed resin or an elastomer is molded, a cross-sectional shape of a plane orthogonal to the axial direction of the shaft member is formed in a C shape or a U shape, and A position opposite to the opening end of the surface material, and on the outer surface of the surface materialPartition line but is formed, The area that was the outer surface of the surface material in the molded state is located on the inside of the surface material when it is wrapped around the shaft member. in the skin material, the partition line is arranged on a surface facing the shaft member in a state of being wound around the shaft member.

[0007] A second aspect of the present invention is, A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. The surface material, in a molded state, has at least a portion of its outer surface formed in a flat shape, and a seating surface for attaching a conductive member is formed therein. A third aspect of the present invention is: A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, ]> In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. A conductive member is fixed to at least a portion of the outer surface in the molded state. The conductive member is a surface material that is an insert member in mold molding. A fourth aspect of the present invention is: ]> A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. The surface material, in its molded state, is provided with reinforcing ribs protruding from the outer surface at positions different from the C-shaped or U-shaped opening ends. A fifth aspect of the present invention is: A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. In the molded state, the molded object is provided with a positioning projection that protrudes outward from the outer surface at a position different from the opening end of the C-shape or U-shape, The surface material is positioned relative to the shaft member by the positioning projection engaging with the shaft member in a state prior to being wrapped around the shaft member.

[0008] In an aspect of the present invention, Sixth includes the above skin material and the shaft member around which the skin material is wound on the outer surface, in a shaft member unit.

[0009] Also, in an aspect of the present invention, Seventh the aspect is 、 A molding process in which a surface material having a C-shaped or U-shaped cross-section and a parting line on its outer surface is formed by molding a foamed resin or elastomer, The process includes a winding step of inverting the inner and outer surfaces of the surface material and winding it around the outer surface of the shaft member. 、 The molding process involves molding the surface material with the conductive member positioned as an insert member in the mold molding process. The method lies in the wrapping of the outer covering material. The eighth aspect of the present invention is, A molding process in which a surface material having a C-shaped or U-shaped cross-section and a parting line on its outer surface is formed by molding a foamed resin or elastomer, The process includes a winding step of inverting the inner and outer surfaces of the surface material and winding it around the outer surface of the shaft member, The process includes a fixing step of fixing a conductive member to the outer surface of the molded surface material, The present invention relates to a method for wrapping a surface material, wherein the wrapping step is performed after the fixing step. [Effects of the Invention]

[0010] With the above configuration, the parting line is not exposed on the outer surface when the outer material is wrapped around the ring, resulting in a better appearance for the outer material.

[0011] Based on the above, it is possible to provide a surface material with improved appearance, a shaft member unit using the surface material, and a method for wrapping the surface material. [Brief explanation of the drawing]

[0012] [Figure 1] This is a front view showing the steering wheel according to Embodiment 1. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] This is a plan view showing the conductive member of Embodiment 1. [Figure 4] This is a cross-sectional view taken along line IV-IV in Figure 3. [Figure 5] This is a cross-sectional view showing a mold for molding the surface material of Embodiment 1. [Figure 6] This is a plan view showing the surface material of Embodiment 1. [Figure 7] This is a side view of the surface material of Embodiment 1, as seen from arrow A in Figure 6. [Figure 8] This is a cross-sectional view taken along line VIII-VIII in Figure 6. [Figure 9] This is a cross-sectional view corresponding to line VIII-VIII in Figure 6, showing the state in which a conductive member is attached to the surface material of Embodiment 1. [Figure 10] This is a flowchart showing the process of wrapping the outer material around the ring portion in Embodiment 1. [Figure 11] This is a cross-sectional view showing the positioning projection of the surface material and the positioning hole of the ring portion facing each other in Embodiment 1. [Figure 12] This is a cross-sectional view showing the state in which the positioning projection of the surface material is fitted into the positioning hole of the ring portion in Embodiment 1. [Figure 13] This is a cross-sectional view showing a state in which a conductive member is installed inside a mold for molding the surface material of Embodiment 2. [Figure 14] This is a cross-sectional view corresponding to the line VIII-VIII in Figure 6, showing the surface material of Embodiment 2. [Figure 15] This is a cross-sectional view corresponding to the line VIII-VIII in Figure 6, showing the surface material of Embodiment 3. [Figure 16] This is a cross-sectional view corresponding to the line VIII-VIII in Figure 6, showing the surface material of Embodiment 4. [Figure 17] This is a cross-sectional view corresponding to the line II-II in Figure 1, showing the state in which the surface material of Embodiment 4 is wrapped around the ring portion. [Figure 18] This is a cross-sectional view showing the surface material of Embodiment 5. [Modes for carrying out the invention]

[0013] (Embodiment 1) The surface material 30 according to Embodiment 1 is used by being wrapped around the steering wheel 10 (an example of a shaft member unit).

[0014] 1. Steering 10 structure The structure of the steering wheel 10 will be described with reference to Figures 1 and 2. As shown in Figure 1, the steering wheel 10 comprises a core portion 11, a ring portion 12, and a plurality of connecting portions 13, 13, 13 that connect the core portion 11 and the ring portion 12. The ring portion 12 has the function of a sensor that detects when a human hand makes contact with it.

[0015] As shown in Figure 1, the ring portion 12 is an axial member whose central axis is a convex curve. In this embodiment, the ring portion 12 is formed in a circular ring shape. In this embodiment, a circular ring shape is considered an example of a convex curve. The surface of the ring portion 12 that is farther from the center of curvature is the outer circumferential surface 14 of the ring portion 12, and the surface of the ring portion 12 that is closer to the center of curvature is the inner circumferential surface 15 of the ring portion 12. However, the ring portion 12 is not limited to a circle and can be formed in any shape.

[0016] As shown in Figure 2, a conductive member 20 and a surface material 30 are attached to the outer surface of the ring portion 12. The ring portion 12 is formed by covering the outer circumference of a core material (not shown) with resin. The resin constituting the ring portion 12 is molded from, for example, foamed resin or elastomer resin. The cross-section perpendicular to the axis of the ring portion 12 is formed in a circular shape. Therefore, the surface of the ring portion 12 has a three-dimensional curved surface over its entire surface, rather than being a single plane. Here, the cross-sectional shape perpendicular to the axis of the ring portion is not limited to a circular shape, but can be any shape such as an ellipse, egg shape, polygon shape, etc.

[0017] A groove 12a is formed around the entire circumference of the inner circumferential surface 15 of the ring portion 12, on the side closer to the center of curvature. A pair of flange portions 33, described later, are fitted and fixed within the groove 12a. The flange portions 33 are an example of engaging protrusions.

[0018] A positioning hole 12b is formed on the outer circumferential surface 14 of the ring portion 12 on the side furthest from the center of curvature. The cross-sectional shape of the positioning hole 12b is not particularly limited, and any shape such as a circular, elliptical, or polygonal shape can be adopted. In this embodiment, the cross-sectional shape of the positioning hole 12b is formed to be square. A positioning projection 34, which will be described later, is fitted into the positioning hole 12b.

[0019] The outer surface of the ring portion 12 is wrapped with a surface material 30. The surface material 30 covers the entire circumference of the ring portion 12 (the entire circumference in the circumferential direction in Figure 2). The surface material 30 is molded from, for example, a foamed resin or an elastomer resin. When wrapped around the ring portion 12, the outer surface of the surface material 30 constitutes a design surface. The surface material 30 will be described in detail later.

[0020] A conductive member 20 is fixed to the inner surface of the outer material 30 while it is wrapped around the outer surface of the ring portion 12. The conductive member 20 is joined to the inner surface of the outer material 30 by known methods such as adhesive bonding or heat fusion. The conductive member 20 is attached to the inner surface of the outer material 30 along the outer circumferential surface 14 on the side furthest from the center of curvature of the ring portion 12, extending around the entire circumference of the ring portion 12. However, the conductive member 20 may be omitted.

[0021] 2. Overall configuration of the conductive member 20 The overall configuration of the conductive member 20 in this embodiment will be described with reference to Figures 3 and 4. Figures 3 and 4 show exaggerated thicknesses for ease of explanation. The conductive member 20 comprises at least an elastomer layer 24, a first electrode layer 25a, and a second electrode layer 25b.

[0022] As shown in Figure 3, the elastomer layer 24 is formed in a long, planar shape. However, since the elastomer layer 24 is flexible and expandable, it can be made into any shape.

[0023] The first electrode layer 25a and the second electrode layer 25b are formed in the shape of flexible, conductive sheets. However, the first electrode layer 25a and the second electrode layer 25b do not have to be in the shape of sheets; they may be formed integrally with a plurality of elastomer layers 24, so that the entire conductive member 20 is formed in the shape of a sheet.

[0024] The elastomer layer 24 is formed, for example, with an elastomer as its main component. Therefore, the elastomer layer 24 is flexible. That is, the elastomer layer 24 is flexible and is configured to be stretchable in the planar direction. The elastomer layer 24 is formed, for example, with a thermoplastic material, particularly a thermoplastic elastomer, as its main component. The elastomer layer 24 may be formed by the thermoplastic elastomer itself, or it may be formed with a crosslinked elastomer formed by heating a thermoplastic elastomer as the main component. Furthermore, the elastomer layer 24 may be composed mainly of a reaction-curable elastomer or a thermosetting elastomer.

[0025] Furthermore, the elastomer layer 24 may contain rubber, resin, or other materials other than thermoplastic elastomers. For example, if the elastomer layer 24 contains rubber such as ethylene-propylene rubber (EPM, EPDM), the flexibility of the elastomer layer 24 will be improved. From the viewpoint of improving the flexibility of the elastomer layer 24, the elastomer layer 24 may contain flexibility-imparting components such as plasticizers.

[0026] Furthermore, the elastomer layer 24 is preferably made of a material with good thermal conductivity. Therefore, the elastomer layer 24 may be made of a thermoplastic elastomer with high thermal conductivity, or it may contain a filler that can increase thermal conductivity.

[0027] The first electrode layer 25a is located on the first surface of the elastomer layer 24, i.e., the surface of the elastomer layer 24 (the upper surface in Figure 4), and the second electrode layer 25b is located on the second surface of the elastomer layer 24, i.e., the back surface of the elastomer layer 24 (the lower surface in Figure 4). The first electrode layer 25a and the second electrode layer 25b are located opposite each other across the elastomer layer 24 (see Figure 3). The first electrode layer 25a and the second electrode layer 25b are formed to be substantially the same shape. Substantially the same includes cases where they are identical, as well as cases where they are not identical but are deemed to be identical.

[0028] The first electrode layer 25a and the second electrode layer 25b constitute the detection electrode. The first electrode layer 25a and the second electrode layer 25b are conductive. Furthermore, the first electrode layer 25a and the second electrode layer 25b are flexible. In other words, the first electrode layer 25a and the second electrode layer 25b are flexible and are configured to be stretchable in the planar direction. The first electrode layer 25a and the second electrode layer 25b are formed from, for example, a conductive cloth, a conductive elastomer, or a metal foil.

[0029] Figure 4 illustrates the case where the first electrode layer 25a and the second electrode layer 25b are made of conductive fabric. The case where the first electrode layer 25a and the second electrode layer 25b are made of conductive fabric will be described in detail. Conductive fabric is a woven or nonwoven fabric made of conductive fibers. Here, conductive fibers are formed by coating the surface of flexible fibers with a conductive material. Conductive fibers are formed, for example, by plating the surface of resin fibers such as polyethylene with copper or nickel.

[0030] In this case, the first electrode layer 25a and the second electrode layer 25b are joined to the elastomer layer 24 by the fusion (thermal fusion) of the elastomer layer 24 itself. Furthermore, since the first electrode layer 25a and the second electrode layer 25b are made of fabric, they have multiple through holes. Therefore, a portion of the elastomer layer 24 penetrates into the through holes of the first electrode layer 25a and the second electrode layer 25b. In other words, at least a portion of the first electrode layer 25a and the second electrode layer 25b becomes embedded in the elastomer layer 24.

[0031] The case in which the first electrode layer 25a and the second electrode layer 25b are formed from a conductive elastomer will be described in detail. In this case, the first electrode layer 25a and the second electrode layer 25b are formed by using an elastomer as the base material and incorporating a conductive filler. The elastomer that is the base material of the first electrode layer 25a and the second electrode layer 25b should have the same main component as the elastomer layer 24. In particular, the first electrode layer 25a and the second electrode layer 25b should be formed from a thermoplastic elastomer.

[0032] However, the first electrode layer 25a and the second electrode layer 25b are formed from materials having a higher softening point than the elastomer layer 24. This is because, when the first electrode layer 25a and the second electrode layer 25b are joined to the elastomer layer 24 by the fusion (thermal fusion) of the elastomer layer 24 itself, the elastomer layer 24 is softened before the first electrode layer 25a and the second electrode layer 25b. As a result, the thickness of the elastomer layer 24 can be set to the desired thickness.

[0033] Here, the first electrode layer 25a and the second electrode layer 25b are joined to the elastomer layer 24 by the fusion (thermal fusion) of the elastomer layer 24 itself. Furthermore, if the first electrode layer 25a and the second electrode layer 25b are formed so that the elastomer is located on the surface, the first electrode layer 25a and the second electrode layer 25b and the elastomer layer 24 are joined by the fusion (thermal fusion) of the first electrode layer 25a and the second electrode layer 25b themselves. In other words, the first electrode layer 25a and the second electrode layer 25b and the elastomer layer 24 are joined by mutual fusion. Note that the first electrode layer 25a and the second electrode layer 25b and the elastomer layer 24 may be joined by fusion of only one of them.

[0034] The case in which the first electrode layer 25a and the second electrode layer 25b are formed from metal foil will be described in detail. The metal foil preferably has multiple through holes, similar to conductive cloth. Therefore, the first electrode layer 25a and the second electrode layer 25b are flexible and can be stretched in the planar direction as the through holes deform. The metal foil can be any conductive metallic material, for example, copper foil or aluminum foil can be used. Furthermore, the first electrode layer 25a and the second electrode layer 25b are joined by fusion (thermal fusion) of the elastomer layer 24 itself, similar to the case of conductive cloth.

[0035] However, the first electrode layer 25a and the second electrode layer 25b may be arranged in parallel along the planar direction on the first surface of the elastomer layer 24.

[0036] The conductive member 20 may be configured such that a heater wire or a shield wire is arranged on the second surface of the elastomer layer 24. Alternatively, the conductive member 20 may be configured such that a heater / shield wire, which serves both as a heater wire and a shield wire, is arranged on the second surface of the elastomer layer 24. Furthermore, the conductive member 20 may be configured such that a heater wire, a shield wire, or a heater / shield wire is arranged on the first or second surface of the elastomer layer 24.

[0037] As shown in Figure 3, the conductive member 20 has through-holes 26 that penetrate the elastomer layer 24, the first electrode layer 25a, and the second electrode layer 25b, through which the positioning projections 34 of the surface material 30 (described later) pass.

[0038] 3.Skin material 30 Next, the surface material 30 will be described with reference to Figures 5 to 9. As shown in Figure 5, the surface material 30 is formed by injecting molten resin into molds 41, 42, 43, and 44, followed by cooling and solidification.

[0039] The molds 41, 42, 43, and 44 include a first mold 41 located on the lower side of Figure 5 and having a first recess 41a that is recessed downwards, a second mold 42 located on the upper side of Figure 5 and having a second recess 42a that is recessed upwards, a shaft mold 43 located in the space between the first recess 41a of the first mold 41 and the second recess 42a of the second mold 42, and a slide mold 44 located to the side of the shaft mold 43 and slidable in the left-right direction in Figure 5. However, the relative positional relationship between the first mold 41 and the second mold 42 is not particularly limited, and the first mold 41 and the second mold 42 may be arranged side by side in the left-right direction.

[0040] The cross-section of the first recess 41a of the first mold 41 is semicircular, and the cross-section of the second recess 42a of the second mold 42 is also semicircular. The cross-section perpendicular to the axis of the shaft mold 43 is circular. A gap is formed between the outer surface of the shaft mold 43 and the inner surfaces of the first recess 41a of the first mold 41 and the second recess 42a of the second mold 42.

[0041] As shown in Figure 5, during injection molding, the right end of the slide mold 44 is in contact with the left side of the shaft mold 43. A gap is formed between the first mold 41 and the second mold 42 in the portion of the slide mold 44 closer to the right end.

[0042] After the molten resin is injected into the gap formed between the first mold 41, the second mold 42, the shaft mold 43, and the slide mold 44, it is cooled and solidified to form the surface material 30.

[0043] As shown in Figures 6 and 7, the surface material 30 comprises a main body portion 31, a seating surface 32, a pair of flange portions 33, and a positioning projection portion 34. The main body portion 31 is formed in a substantially C shape when viewed from a direction perpendicular to the plane of the paper in Figure 6. The opening portion of the substantially C shape is a notch portion 35. A flat seating surface 32 is formed around the entire circumference of the outer surface of the main body portion 31. A conductive member 20 is fixed to the seating surface 32 (see Figure 9).

[0044] As shown in Figure 7, a parting line 36 is formed on the outer surface of the seat surface 32. The parting line 36 is formed on the surface material 30 at a position corresponding to the mating surface between the first mold 41 and the second mold 42 in Figure 5. The parting line 36 is formed around the entire circumference of the outer surface of the seat surface 32. However, the seat surface 32 may be omitted, in which case the parting line 36 may be formed on the outer surface of the main body 31.

[0045] As shown in Figure 8, the cross-sectional shape of the main body portion 31 perpendicular to the axial direction of the ring portion 12 is C-shaped. The term C-shaped includes cases where it is C-shaped, as well as cases where it is not C-shaped but can be substantially recognized as C-shaped. A pair of flange portions 33 (an example of engaging projections) are formed on the pair of ends of the main body portion 31 that form the open ends of the C-shape, extending along the axial direction of the ring portion 12 and projecting outward from the pair of ends. The projection dimension of the flange portions 33 from the main body portion 31 is formed to be constant around the entire circumference. However, the projection dimension of the flange portions 33 from the main body portion 31 may be formed to differ depending on the location.

[0046] When the flange portion 33 is wrapped around the ring portion 12, it fits into the groove portion 12a formed in the ring portion 12. The depth dimension of the groove portion 12a of the ring portion 12 is the same as or slightly larger than the protruding height dimension of the flange portion 33 from the main body portion 31. The flange portion 33 is fixed by adhesive injected into the groove portion 12a. This prevents the surface material 30 from deforming in the opening direction.

[0047] On the outer surface of the skin material 30, a positioning projection 34 is formed that protrudes outward, on the side opposite to the notch 35 described above. The cross-sectional shape of the positioning projection 34 is not particularly limited, and any shape such as a circular, elliptical, or polygonal shape can be adopted. In this embodiment, the cross-sectional shape of the positioning projection 34 is formed to be rectangular. The positioning projection 34 is formed directly above the parting line 36, and the parting line 36 is also formed on the positioning projection 34. However, the positioning projection 34 may also be formed on the part of the main body 31 where the parting line 36 is not formed.

[0048] The positioning projection 34 is configured to fit into the positioning hole 12b formed in the ring portion 12 during the contact process described later. The depth dimension of the positioning hole 12b in the ring portion 12 is the same as or slightly larger than the projection height dimension of the positioning projection 34 from the seating surface 32.

[0049] The inner surface of the main body 31 may be a smooth curved surface, or it may have various patterns such as textures or dimples formed on it. According to this embodiment, since various patterns can be formed on the inner surface of the main body 31, multiple patterns can be combined. For example, it is possible to form multiple textured patterns on the inner surface of a single main body 31.

[0050] 4. Method of wrapping the outer covering material 30 Next, an example of how to wrap the surface material 30, to which the conductive member 20 is fixed, around the ring portion 12 of the steering wheel 10 will be explained in Figures 2, 5, and 8-12. Note that the method of wrapping the surface material 30 is not limited to the description below.

[0051] First, as shown in Figure 5, the surface material 30 is formed into a predetermined shape by injection molding (Figure 10, molding process S1). After the resin injected into the molds 41, 42, 43, and 44 has solidified, the surface material 30 is removed from the mold (see Figure 8).

[0052] Next, as shown in Figure 9, a sheet-like conductive member 20 is joined and fixed to a seating surface 32 formed in a planar shape on the outer surface of the skin material 30 (Figure 10, fixing step S2). At this time, the positioning projection 34 of the skin material 30 is passed through the through hole 26 of the conductive member 20. The seating surface 32 and the conductive member 20 may be bonded together with an adhesive, or one or both of the seating surface 32 and the conductive member 20 may be heat-fused together.

[0053] Adhesive is applied to the outer surface of the skin material 30 to which the conductive member 20 is fixed. Adhesive is also applied to the outer surface of the ring portion 12 (Figure 10, application step S3). Adhesive is also injected into the positioning hole 12b and groove portion 12a of the ring portion 12.

[0054] As shown in Figure 11, the surface material 30 and the ring portion 12 are positioned so that the positioning projection 34 of the surface material 30 and the positioning hole 12b of the ring portion 12 face each other.

[0055] As shown in Figure 12, the positioning projection 34 of the surface material 30 is inserted into the positioning hole 12b of the ring portion 12, bringing the outer surface of the positioning projection 34 into contact with the inner surface of the positioning hole 12b (Figure 10, contact step S4). This ensures the relative positioning of the surface material 30 and the ring portion 12.

[0056] Next, as shown by arrow B in Figure 12, the outer material 30 is inverted. This causes the outer material 30, to which the conductive member 20 is fixed, to be wrapped around the outer surface of the ring portion 12 (Figure 10, wrapping process S5). That is, the outer material 30 is wrapped around the outer surface of the ring portion 12 along the circumferential direction perpendicular to the axis of the ring portion 12. The pair of flange portions 33 of the outer material 30 are fitted into the groove portion 12a of the ring portion 12. Then, as shown in Figure 2, the pair of flange portions 33 are fixed within the groove portion 12a by the adhesive injected into the groove portion 12a and the adhesive applied to the pair of flange portions 33. This prevents the outer material 30 from deforming back and opening in the opposite direction to the arrow in Figure 12.

[0057] Furthermore, the surface material 30 is stretched circumferentially with respect to the center of curvature of the ring portion 12. As a result, the ends of the surface material 30 that constituted the notch 35 of the surface material 30 come into contact with each other. This ensures that the ring portion 12 is covered by the surface material 30 around its entire circumference. Consequently, the ring portion 12 is protected by the surface material 30, thus preventing contact between the ring portion 12 and chemicals such as disinfectants and oils. This allows for a lower requirement for chemical resistance performance of the conductive member 20, thereby reducing the manufacturing cost of the surface material 30.

[0058] When the outer material 30 is wrapped around the ring portion 12, the area that was the outer surface of the outer material 30 at the end of molding becomes located on the inside of the outer material 30, facing the outer surface of the ring portion 12. Similarly, the area that was the inner surface of the outer material 30 at the end of molding becomes located on the outside of the outer material 30.

[0059] When wrapped around the ring portion 12, the parting line 36 formed on the surface material 30 is located on the inside of the surface material 30. In other words, the parting line 36 is not exposed on the outer surface of the surface material 30.

[0060] Subsequently, the adhesive hardens, fixing the outer material 30 and the ring portion 12 in place. This completes the process of wrapping the outer material 30 around the ring portion 12. After that, the connecting portion 13 and the core portion 11 are attached to the ring portion, completing the steering wheel 10.

[0061] 5. Effects Next, the effects of this embodiment will be explained below. The surface material 30 according to this embodiment is wrapped around the ring portion 12 of the steering wheel 10 along the circumferential direction of the ring portion 12. The surface material 30 is formed from a foamed resin or elastomer in a molded state, with a cross-sectional shape in a plane perpendicular to the axial direction of the ring portion 12 being C-shaped, and a parting line 36 is formed on its outer surface. The parting line 36 is positioned on the surface facing the outer surface of the ring portion 12 when the surface material 30 is wrapped around the ring portion 12.

[0062] As a result, the parting line 36 is not exposed on the outer surface when the outer material 30 is wrapped around the ring portion 12, thus improving the appearance of the outer material 30. In addition, since any shape can be formed on the inner surface in the molded state, the degree of freedom in molding the outer material 30 is improved. Furthermore, since any pattern can be formed on the inner surface in the molded state, the manufacturing cost of the outer material 30 can be reduced.

[0063] In this embodiment, the surface material 30 has a conductive member 20 fixed to at least a portion of its outer surface in a molded state. This allows the conductive member 20 fixed to the surface material 30 to be used as an electrostatic transducer or heater.

[0064] In this embodiment, the surface material 30, in its molded state, has at least a portion of its outer surface formed in a flat shape, and a seating surface 32 to which the conductive member 20 is attached is formed. Because the seating surface 32 is formed in a flat shape, the conductive member 20 can be easily attached. This is particularly effective when the conductive member 20 is formed in a sheet shape.

[0065] The surface material 30 in this embodiment has a flange portion 33 on its outer surface when molded. When the surface material 30 is wrapped around the ring portion 12, the flange portion 33 engages with a groove portion 12a formed in the ring portion 12. When wrapped around the ring portion 12, the flange portion 33 engages with the groove portion 12a of the ring portion 12, thereby positioning the ring portion 12 and the surface material 30.

[0066] In this embodiment, the flange portion 33 is formed on both ends of a pair of ends that form a C-shaped opening.

[0067] In this embodiment, the flange portion 33 is configured in a molded state as a pair of flange portions 33 that extend at least along the axial direction and protrude outward at the pair of C-shaped ends. The pair of flange portions 33 are shaped to protrude toward the ring portion 12 when wrapped around the ring portion 12. When the surface material 30 is wrapped around the ring portion 12, the pair of flange portions 33 engage with the groove portion 12a of the ring portion 12. As a result, the C-shaped open end can be engaged with the ring portion 12 via the flange portion 33, thereby suppressing deformation of the pair of ends of the surface material 30 in a direction away from the ring portion 12.

[0068] The surface material 30 in this embodiment, in its molded state, has a positioning projection 34 that protrudes outward from the outer surface at a position different from the C-shaped opening end. Before being wrapped around the ring portion 12, the surface material 30 is positioned relative to the ring portion 12 by the positioning projection 34 engaging with a positioning hole 12b formed in the ring portion 12. By engaging the positioning projection 34 with the positioning hole 12b of the ring portion 12 before the surface material 30 is wrapped around the ring portion 12, the surface material 30 can be positioned on the ring portion 12. This improves the efficiency of the work of wrapping the surface material 30 around the ring portion 12.

[0069] The ring portion 12 in this embodiment has a three-dimensional curved surface. A three-dimensional curved surface cannot be formed simply by bending a flat surface. Applying the surface material 30 of this embodiment to the ring portion 12 having such a three-dimensional curved surface is effective.

[0070] The ring portion 12 in this embodiment is an annular member. The surface of the annular member is a three-dimensional curved surface as described above. Therefore, as in this embodiment, the surface material 30 can be applied to an annular member such as the steering wheel 10.

[0071] This embodiment is a steering wheel 10 comprising the above-described surface material 30 and a ring portion 12 on which the surface material 30 is wrapped around the outer surface. According to this embodiment, the appearance of the steering wheel 10 can be improved by applying the surface material 30 to the ring portion 12.

[0072] The method for wrapping the surface material 30 according to this embodiment comprises a molding step of forming a surface material 30 having a C-shaped cross-section and a parting line 36 on its outer surface by molding a foamed resin or elastomer, and a wrapping step of inverting the inner and outer surfaces of the surface material 30 and wrapping it around the outer surface of the ring portion 12. When the surface material 30 is wrapped around the ring portion 12, the parting line 36 is located on the inside, which improves the appearance of the surface material 30.

[0073] The method for wrapping the outer material 30 according to this embodiment includes a coating step of applying adhesive to the outer surface of the molded outer material 30 or the outer surface of the ring portion 12, and the wrapping step is performed after the coating step. According to this embodiment, the manufacturing process can be simplified compared to the case in which the outer material 30 is sewn after being wrapped around the ring portion 12. In addition, since the adhesive only needs to be applied to the outer surface of the outer material 30 or the outer surface of the ring portion 12, work efficiency can be improved.

[0074] In the method for winding the surface material 30 according to this embodiment, the winding step involves bringing a portion of the outer surface of the molded surface material 30 into contact with the outer surface of the ring portion 12, and then inverting the inner and outer surfaces of the surface material 30 and winding it around the outer surface of the ring portion 12. By bringing a portion of the outer surface of the surface material 30 into contact with the outer surface of the ring portion 12, the surface material 30 can be positioned relative to the ring portion 12. In this way, since the surface material 30 can be wound around the ring portion 12 after positioning the surface material 30 and the ring portion 12, the efficiency of the winding work of the surface material 30 can be improved.

[0075] The winding process for the surface material 30 in this embodiment includes a fixing step in which the conductive member 20 is fixed to the outer surface of the molded surface material 30, and the winding step is performed after the fixing step. This improves the efficiency of the fixing process between the surface material 30 and the conductive member 20 compared to the case where the conductive member 20 is fixed to the inner surface of the C-shaped surface material 30.

[0076] (Embodiment 2) Next, the surface material 50 of Embodiment 2 will be described with reference to Figures 13 and 14. As shown in Figure 13, a first mounting recess 53 is formed on the inner surface of the first mold 51, to which the first conductive member 52 is attached. Also, a second mounting recess 56 is formed on the inner surface of the second mold 54, to which the second conductive member 55 is attached. The first conductive member 52 and the second conductive member 55 are examples of conductive members.

[0077] As shown in Figure 13, the first conductive member 52 is held in a position relative to the first mold 51 within the first mounting recess 53 by known engaging means. Similarly, the second conductive member 55 is held in a position relative to the second mold 54 within the second mounting recess 56 by known engaging means. The first conductive member 52 and the second conductive member 55 are configured to be easily removed from the first mold 51 and the second mold 54, respectively, when the molds are opened.

[0078] After the resin is injected into the gaps between the first mold 51, the second mold 54, the shaft mold 43, and the slide mold 44, it is allowed to solidify. The first conductive member 52 and the second conductive member 55 then become integrated with the solidified resin. This allows the surface material 50 and the first conductive member 52 and the second conductive member 55 to be integrated during the molding process. However, the number of conductive members attached to the first mold 51 and the second mold 54 may be one or three or more. Afterward, the first mold 51 and the second mold 54 are opened and the surface material 50 is removed.

[0079] As shown in Figure 14, the first conductive member 52 and the second conductive member 55 are fixed to the outer surface of the molded surface material 50. Parts of the first conductive member 52 and the second conductive member 55 are embedded inside the surface material 50. In addition, parts of the first conductive member 52 and the second conductive member 55 may be integrated with parts of the surface material 50.

[0080] The configuration other than that described above is substantially the same as in Embodiment 1, so the same reference numerals are used for the same components, and redundant explanations are omitted.

[0081] In this embodiment, a portion of the first conductive member 52 and the second conductive member 55 serves as an insert member in the mold forming process. Furthermore, in the winding process of the skin material 50 according to this embodiment, the molding process molds the skin material 50 with a portion of the first conductive member 52 and the second conductive member 55 positioned as an insert member in the mold forming process. This allows the conductive member 20 to be integrated when the skin material 50 is molded, thereby streamlining the manufacturing process.

[0082] (Embodiment 3) Next, Embodiment 3 will be described with reference to Figure 15. The surface material 60 in this embodiment has a U-shaped cross-section perpendicular to its axis. A flange portion 33 that protrudes outward is formed at one end of the U-shaped opening.

[0083] The configuration other than that described above is substantially the same as in Embodiment 1, so the same reference numerals are used for the same components, and redundant explanations are omitted.

[0084] (Embodiment 4) Next, Embodiment 4 will be described with reference to Figures 16 to 17. As shown in Figure 16, the surface material 70 according to this embodiment has reinforcing ribs 71 that protrude outward from the outer surface at positions different from the C-shaped opening end. The surface material 70 of this embodiment has two reinforcing ribs 71. Each reinforcing rib 71 is formed in the region of the surface material 70 between the C-shaped opening end and the positioning projection 34. The reinforcing ribs 71 are formed along the axial direction. The protrusion dimension of the reinforcing ribs 71 from the outer surface of the surface material 70 is formed to be constant along the axial direction. The strength of the surface material 70 can be improved by the reinforcing ribs 71. However, the number of reinforcing ribs 71 may be one or three or more. Also, the reinforcing ribs 71 may be formed along a direction intersecting the axial direction. Furthermore, the protrusion dimension of the reinforcing ribs 71 from the outer surface of the surface material 70 is not particularly limited and may be configured to vary along the axial direction.

[0085] As shown in Figure 17, when wrapped around the ring portion 72, the reinforcing ribs 71 of the surface material 70 are fitted into relief grooves 73 formed on the outer surface of the ring portion 72. The depth of the relief grooves 73 is the same as or greater than the protrusion of the reinforcing ribs 71 from the outer surface of the surface material 70. By fitting the reinforcing ribs 71 into the relief grooves 73, movement of the surface material 70 along the circumferential direction of the ring portion 72 is suppressed.

[0086] The configuration other than that described above is substantially the same as in Embodiment 1, so the same reference numerals are used for the same components, and redundant explanations are omitted.

[0087] (Embodiment 5) Next, Embodiment 5 will be described with reference to Figure 18. In this embodiment, the surface material 80 is in an inverted state of the molded surface material 80. That is, the surface material 80 is formed in a C shape, and a parting line 36 is formed on the inner surface of this C shape. On the inner surface of the surface material 80, a seating surface 32 with a planar shape is formed at a position opposite to the open end of the C shape. In addition, a pair of flange portions 33 that protrude inward are formed on the pair of open ends of the C shape.

[0088] The configuration other than that described above is substantially the same as in Embodiment 1, so the same reference numerals are used for the same components, and redundant explanations are omitted.

[0089] The surface material 80 in this embodiment has a C-shaped cross-sectional shape in a plane perpendicular to the axial direction, and a parting line 36 is formed on the inner surface. However, the cross-sectional shape of the surface material 80 may be U-shaped.

[0090] By attaching the surface material 80 to the ring portion 12 such that the outer surface of the ring portion 12 and the inner surface of the surface material 80 face each other, the parting line 36 is not exposed on the outer surface, thereby improving the appearance of the surface material 80.

[0091] The technologies disclosed herein are not limited to the embodiments described above in the description and drawings, but also include various other embodiments, such as the following:

[0092] The shape of the ring portion of the steering wheel 10 is not limited to annular. For example, the ring portion of the steering wheel 10 may be formed in a roughly D-shape, or in a square shape, or any other shape. [Explanation of symbols]

[0093] 10 Steering 12, 72 Ring section 20 Conductive members 30, 50, 60, 70, 80 Skin material 36 parting lines S1 Molding process S5 Winding process

Claims

1. A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface of the surface material at a position opposite to the open end of the surface material. The area that was the outer surface of the surface material in the molded state is located on the inside of the surface material when it is wrapped around the shaft member. A surface material in which the parting line is positioned on the surface facing the shaft member when wrapped around the shaft member.

2. The surface material according to claim 1, wherein a conductive member is fixed to at least a portion of the outer surface in a molded state.

3. The surface material according to claim 1, wherein, in a molded state, at least a portion of the outer surface is formed to be flat, and a seating surface for attaching a conductive member is formed.

4. The surface material according to claim 2, wherein the conductive member is an insert member in mold forming.

5. A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. A surface material in which, in a molded state, at least a portion of the outer surface is formed to be flat, and a seating surface for attaching a conductive member is formed.

6. A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. A conductive member is fixed to at least a portion of the outer surface in the molded state. The conductive member is a surface material that is an insert member in mold molding.

7. The surface material according to any one of claims 1 to 6, comprising an engaging projection that protrudes from the outer surface in a molded state, wherein the engaging projection engages with the shaft member when wrapped around the shaft member.

8. The surface material according to claim 7, wherein the engaging projection is formed on at least one of a pair of ends that form the C-shaped or U-shaped open ends.

9. In the molded state, the engaging projection is configured as a pair of flanges that extend at least along the axial direction and project outward at the pair of ends. The surface material according to claim 8, wherein the pair of flange portions are shaped to protrude toward the shaft member when wrapped around the shaft member.

10. The surface material according to any one of claims 1 to 9, wherein, in the molded state, it is provided with reinforcing ribs protruding from the outer surface at positions different from the C-shaped or U-shaped opening ends.

11. In the molded state, the molded part is provided with a positioning projection that protrudes outward from the outer surface at a position different from the opening end of the C-shape or U-shape, The surface material according to any one of claims 1 to 10, wherein, in a state prior to being wrapped around the shaft member, the positioning projection engages with the shaft member to position it relative to the shaft member.

12. A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. A surface material having reinforcing ribs protruding from the outer surface at positions different from the C-shaped or U-shaped opening ends when molded.

13. A skin material that is wrapped around at least a portion of the shaft member along the circumferential direction of the shaft member, In a molded state, the foamed resin or elastomer has a cross-sectional shape in a plane perpendicular to the axial direction of the shaft member that is C-shaped or U-shaped, and a parting line is formed on the outer surface. The parting line is positioned on the surface facing the shaft member when it is wrapped around the shaft member. In the molded state, the molded part is provided with a positioning projection that protrudes outward from the outer surface at a position different from the opening end of the C-shape or U-shape, A surface material that, in a state prior to being wrapped around the shaft member, is positioned relative to the shaft member by the positioning projection engaging with the shaft member.

14. The shaft member is a surface material according to any one of claims 1 to 13, having a three-dimensional curved surface.

15. The surface material according to any one of claims 1 to 14, wherein the shaft member is an annular member.

16. A surface material according to any one of claims 1 to 15, A shaft member unit comprising the shaft member on which the surface material is wrapped around the outer surface.

17. A molding step of forming a surface material having a C-shaped or U-shaped cross-section and a parting line on its outer surface by molding a foamed resin or elastomer, The process includes a winding step of inverting the inner and outer surfaces of the surface material and winding it around the outer surface of the shaft member, The molding process is a method for wrapping a surface material, wherein the surface material is molded with a conductive member positioned as an insert member in mold molding.

18. A molding step of forming a surface material having a C-shaped or U-shaped cross-section and a parting line on its outer surface by molding a foamed resin or elastomer, The process includes a winding step of inverting the inner and outer surfaces of the surface material and winding it around the outer surface of the shaft member, The process includes a fixing step of fixing a conductive member to the outer surface of the molded surface material, A method for wrapping a surface material, wherein the wrapping step is performed after the fixing step.

19. The process includes a coating step of applying adhesive to the outer surface of the molded surface material or the outer surface of the shaft member, A method for wrapping a surface material according to claim 17 or 18, wherein the wrapping step is performed after the coating step.

20. The method for winding a surface material according to any one of claims 17 to 19, wherein the winding step involves bringing a portion of the outer surface of the molded surface material into contact with the outer surface of the shaft member, and then inverting the inner and outer surfaces of the surface material and winding it around the outer surface of the shaft member.

Images